Electric weft detector for shuttle changing looms



Nov. 22, 1949 H. A. WHITIN ELECTRIC WEFT DETECTOR FOR SHUTTLE CHANGING LOOMS Filed Dec. '50, 1948 80/ PIC-3.7

ATTORNEY Patented Nov. 22, 1949 ELECTRIC WEFT DETECTOR FOR SHUTTLE CHANGING LOOMS Herbert A. Whitin, Worcester, Mass, assignor to Crompton' & Knowles Loom Works, Worcester, Mass, a corporation of Massachusetts Application'December 30, 1948, Serial No. 68,151

'7 Claims.

This invention relates to electromechanical weft detecting systems for shuttle changing looms and it is the general object of the invention to provide means by which a false indication of weft exhaustion by the detector incident to a shuttle changing operation will be prevented from initiating another shuttle changing operation.

In a type of multicolor shuttle changing loom which has gone into general use a magazine employing two stacks of reserve shuttles is located adjacent to two shifting shuttle boxes which are normally at rest with respect to the lay, but rise to permit the upper box to receive a selected shuttle from the magazine when the lay is on back center. The, depleted shuttle enters the lower box which is temporarily aligned with the shuttle race. The boxes then fall to place the fresh shuttle in picking position and also eject the depleted shuttle. Shifting of the shuttle boxes occurs when the lay is in the forward part of its motion and is ordinarily in progress when the lay is on front center. The weft detector is located at the magazine end of'the 100m and in order to prevent its breakage by the shifting boxes provision is generally made to move the feeler or weft detector forwardly out of the path of the boxes on shuttle changing beats of the loom.

When an electric weft detector of the side slip type is employed in such aloom it is likely because of its momentum to swing and give a false indication incident to forward and return movement from-its normal. position to clear the shifting shuttle boxes. When such a feeler is used with an electric weft detecting system there is likelihood that' the circuit will be closedby'thefalse indication and a second unnecessary shuttle changing operation will follow.

It is an important object of the present invention to provide the electric weft detector system with a second switch which will be open when the detector is forward of its normal position on shuttle changing beats of the loom, thereby insuring that the detector circuit cannot be closed even though the feeler finger should have a false side slipping movement.

In shuttle changing looms of the type already mentioned it is customary to mount the feeler on an arm or the like pivoted to a fixed stand and it is a further object of the invention to control the second switch in the electric circuit by relative movement of the arm with respect to the stand.

With these and. other objects in view which will appear as the descri-ptionproceeds, the invention resides in the combination and arrangement of parts hereinafter described and set forth.

In the accompanying drawings, wherein a convenient embodiment'of'the invention is set forth,

Fig. 1 is a side elevation of part of a multicolor weft" replenishing loom showing the lay, shuttle boxes and cover therefor in crosssection,

Fig. 2 is an enlarged plan view partly in section looking inthe direction of arrow 2, Fig; 1, showing the weft detector innormal position in full lines and in indicating position in dotted lines,

Fig. 3 is an enlarged vertical section on line 3-3 of Fig. 2,

Fig. 4 is an enlarged diagrammatic view of the structure shown at the left of Fig. 1 indicating the parts in two different'positions,

Fig. 5 is an enlarged'transverse section on line 5-5,' Fig. 4, showing the second switch in closed position,

Fig. 6 is a viewsimilar to Fig. 5 but showing the switch open, and

Fig. 7 is a diagram showing the electric circuit used. with the invention.

Referring more particularly. to Fig. 1, the loom frame III supports-a reserve shuttle magazine M having front and backstacksv II and. I2, respectively, of reserveshuttles which. may have weft of two difierent characteristics. The. shuttles of the front stack are supported by a lever I3 connected by rod I4 to another lever I 5. The latter is connectedlby, a rod I6 to control mechanism not shown herein but well understood. The shuttles of the rear stack I2 rest on a support I! and. the lowest shuttle in stack I2 is in front of a plunger I8 controlled by a lever I9 which in. turn is connected to another rod 20 which also extends to the control mechanism to which rod. I6. extends. When a shuttle from the front stack is to be released rod I6 is depressedto effect. rocking of lever I3, whereupon the bottom shuttle. of. stack II falls into a common compartmentZI below stack II and in front of the .bottom shuttle in stack I2. If, on the other hand, areplenishing. operation involves a shuttle from the rear stack. rod 20. will be depressed so that the plunger I8 willmove the lowest shuttle of stack I2 into the common compartment 2|. A support 22.extending rearwardly from the lay 23 will. hold the released shuttle until the lay reaches back center.v

Shuttle change is effected by means of a gang G Of shuttle boxes having upper and lower cells or. boxes 25. and. 26, respectively, mounted on a box. lifter rod 21. These shuttle boxes are normally down' as shownv in.-Fig. 1 so that the top shuttle box 25 is active and receives a shuttle on every other beat of the loom. When a shuttle changing operation is called rod 2'5 is lifted to place the lower cell or shuttle box 26 in active position to receive the oncoming depleted shuttle and at the same time the upper shuttle box 25 is raised to a position where it can receive a reserve shuttle in the compartment 2|.

The shuttle box structure has pivoted thereto a cover 28 provided with a stud 29 for cooperation with a cam 39 fixed to the magazine in stationary position. The boxes ordinarily shift while the lay is in the forward part of its motion when the I stud 29 is forward of the cam 33 and as the shuttle boxes rise the stud is caused to register with the cam so that the subsequent rearward movement of the lay will rock the cover in a counterclockwise direction as viewed in Fig. l to open the top of shuttle box 25 so that it can receive the reserve shuttle from compartment 21.

The weft detector D is located on the same side of the loom as the magazine and is in front of the shuttle boxes. Ordinarily this detector is in stationary position and enters the shuttle box 25 to detect the condition of weft in the shuttle therein when the lay beats up to front center. Since the boxes shift at front center breakage of the detector would result unless it were moved forwardly. Provision is usually made for mounting the detector so that it can be moved forwardly by the structure shown at the left of Fig. l.

A stationary support 35 fixed with respect to the magazine M carries a stud or similar pivot 36 on which is mounted a detector supporting arm 3'1. A spring 38 interposed operatively between the arm 31 and a part of the support 35 normally holds the arm 3'1 in the position shown in Fig. l with the detector in its normal detecting position. A pressure member Gil is pivoted as at GI to the arm 3i and is normally in such position that the cover 23 moves under it when the lay approaches front center. When the boxes are rising, however, incident to a shuttle changing operation the cover engages the member 4% and forces the latter forwardly against a pin 42 on the arm 31,

thereby rocking the latter in a clockwise direction as viewed in Fig. 1 around the pivot 36. The detector D is thus moved forwardly to a position where it cannot interfere with or be broken by the shifting boxes 25 and 25.

The matter thus far described is of common construction and may be made as set forth in prior Patent No. 2,103,800.

The control mechanism for the rods i6, 20 and 21 includes a solenoid designated at S in Fig. 7. When this solenoid is energized due to indication of weft exhaustion by detector D a shuttle changing operation is initiated. This solenoid may be the same as that shown. in the aforesaid patent and control the various parts of the magazine and shuttle boxes as set forth therein.

In the past it has been customary to make the weft detector of two prongs of opposite polarity which will be insulated from each other during detecting operations when there is sufficient weft in the shuttle being detected, but when the weft is depleted a ferrule carried by the shuttle will be exposed and electrically connect the prongs of the detector, thereby energizing the solenoid.

A detector of this type requires a ferrule on every bobbin used in the loom and in order to avoid the expense'of these ferrules it is proposed to use a side slip electrmmechanical detector which will operate with the usual bobbin made without a ferrule. Such a detector is shown for instance in Figs. 2 and 3 wherein the arm 31 is shown as being provided with a foot to which a detector carrier plate 46 is bolted as at 41. Plate it has secured thereto an upstanding stud it on which is pivotally mounted a detector arm 49. A coil spring surrounds stud 48 and has one end thereof connected to the arm or finger t5 and has the other end thereof connected to a drum or shell 5| surrounding the stud 48. A set screw 52 affords means for fastening the drum in adjusted angular position to the stud 4B for the purpose of varying the force exerted by the spring 5% Supported by the arm 49 at one side of the pivot stud 48 is a horizontal tube in which is slidably mounted a detector finger 56 the rear end of which has a tip 51 for engagement with the bobbin B in shuttle box 25. A light compression spring 58 within the tube 55 surrounds the forward end of the rod or finger 5B and serves in well-known manner to hold the latter and therefore the tip rearwardly in detecting position. When sufficient weft is present during the detecting operation to resist side slipping movement of the tip 51, the rod 56 moves forwardly against the action of spring 58 without causing substantial angular motion of the arm 49. When the bobbin is depleted of weft, however, a smooth surface thereof is presented to the tip and the latter slides laterally to the dotted line position shown in Fig. 2, thereby causing angular motion of the arm 49.

As shown in Fig. 3 the plate 46 has secured to the under side thereof a switch 60 which has a control plunger or pin 6| which when pushed inwardly, or rearwardly toward arm 49 as viewed in Fig. 2, causes the switch to be open, but when the plunger moves forwardly the switch automatically closes. Position of the plunger is conrolled by a preferably resilient plate or arm 63 pivoted as at 62 with respect to the plate 45. This arm extends to the left as viewed in Fig. 2 to a position behind a finger 64 which projects forwardly from arm 49 and then downwardly, see Fig. 3. The plunger Bl normally exerts a forward pressure on the leaf spring 63 which, however, is not sufficiently strong to overpower the spring 50. When the detector finger 56 slides forwardly on a non-indicating beat of the loom the finger 64 maintains the left end of the leaf spring 63 in rear position, thereby keeping the plunger 6| in its normal rearward position with respect to the switch so to keep the latter open. When the detector indicates weft exhaustion, however, angular movement of arm 49 moves the finger 64 forwardly away from controlling position with respect to the leaf spring 63 and the latter permits the plunger 6| to move forwardly and close switch til. In this manner the detector effects closure of the switch 68 whenever it has a side slipping movement, as when indicating weft exhaustion.

It will be apparent that the greater part of the weight of the arm 49 and parts supported thereby is at one side of the pivot 48, and as the support arm 37 moves the detector to positions forward of its normal position the detector is likely to swing in a counter-clockwise direction as viewed in Fig. 2 about the stud 48 to give a false indication of weft exhaustion, thereby effecting closure of the switch 50, although at this time it is undesirable to have the switch closed. Under these conditions the detector would call a second shuttle changing operation of the loom unless provision were made to prevent closure of the detector circuit.

In order that the false closing of the switch 60 may be prevented from energizing the solenoid S when the detector is moved forwardly there is provided a second switch having a spring contact H for engagement with a fixed contact 12. The switch Ill is provided with a plunger 13 similar to plunger fil, except that its effect is the reverse of the latter named plunger. When the plunger is moved into the switch 10 the contacts H and 12 are in electric engagement with each other as shown in Fig. 5, but when the plunger 13 is free to move forwardly under action of the resilient contact H the two contacts are open, see Fig. 6.

Switch 10 is mounted on the detector support arm 31 by means of a plate 15 fastened as at 16 to the arm 31. The plunger I3 is posi tioned for engagement with the support 35, and when the parts are held in their normal position as shown in Fig. l the support effects movement of the plunger 13 to the position shown in Fig. 5. At this time the switch 10 is in the full line position shown in Fig. 4. When the detector is moved forwardly, however, by engagement of' the cover 28 with member 40 the carrier t'i swingsupwardly around pivot 36 to the dotted line position shown in Fig. 4. This effects lifting of the switch Hirelatively to support 35 with consequent movement of the plunger 13 downwardly withrespect to the; switch 10.

The resilient contact ll thereupon moves the plunger 13 to the position shown in Fig. 6 and moves away from contact 12, thereby opening the switch 10.

' The circuit for operating the aforesaid solenoid, shown in Fig. 7, is normally as follows: transformer T, a wire 80, solenoid S, wire 8|, normally open detector switch 60, wire 82, normally closed control switch 10, and wire 83 back to the transformer. When switch 60 is closed by a normal and proper indication of weft exhaustion by the detector solenoid S will be energized, because at this time switch 10 is closed. During a shuttle changing operation, however, when the detector D gives a false indication, control switch H1 will be open and the circuit shown in Fig. '7 cannot be closed, therefore the solenoid will not be energized.

From the foregoing it will be seen that the invention sets forth simple means by which a side slipping electromechanical weft detector can be used on a shuttle changing loom without danger that the detector circuit will be closed by a false indication of the detector when the latter is moved out of the path of the shifting shuttle boxes incident to a shuttle changing operation of the loom. This result is accomplished by having a second or control switch in the circuit normally closed but so controlled as to open and therefore interrupt the detector circuit whenever the detector is moved forwardly by the box cover 28. Rearward movement of the lay from its front center position while the boxes 25 and 26 are rising permits spring 38 to return the detector to its normal position, but by the time this normal position is attained the detector arm 49 will have returned to its normal position so that detector switch 50 will be open when switch 10 closes.

Having thus described the invention it will be seen that changes and modifications of the foregoing specific disclosure may be made without departing from the spirit and scope of the invention.

What is claimed as new is:

1. In a shuttle changing loom having a lay provided with shuttle boxes which shift incident to a shuttle changing operation of the loom, a

weft detector normally positioned to detect the condition of weft in one of said boxes, means giving thedetector a. movement in a direction away from the boxes on shuttle changing operations of the loom, the detector tending due to said'movement to give a false indication of weft exhaustion, shuttle changing controlling electric circuit means including a normally open electric switch closed whenever the detector indicates weft exhaustion and including also a normally closed switch, said circuit means being closed only when both switches are closed, and meanseffecting opening of the normally closed switch on shuttle changing operations of the loom.

2. In a shuttle changing loom having a lay provided with shuttle boxes which shift incident to a shuttle changing operation of the loom, a weft detector normally positioned to detect the condition of weftin one of said boxes but receiving a movement derived from the lay and due toshifting of the shuttle boxes in a direction away from the boxes on shuttle changing operations of the loom and tending due to said movement to give afalse indication of weft exhaustion, shuttle changing controlling electric circuit means including a normally open electric switch closed whenever the detector indicates weft exhaustion and including also a normally closed switch, said circuit means being closed only when both switches are closed, and means effecting opening of the normally closed switch by a force derived from th lay on shuttle changing operations of the loom.

3. In a shuttle changing loom having a lay provided with shuttle boxes which shift incident to a shuttle changing operation of the loom, a weft detector normally positioned to detect the condition of weft in one of said boxes but receiving a movement derived from the lay and due to shifting of the shuttle boxes in a direction away from the boxes on shuttle changing operations of the loom and tending due to said movement to give a false indication of weft exhaustion, shuttle changing controlling electric circuit means including a normally open electric switch closed whenever the detector indicates weft exhaustion and including also a normally closed switch, said circuit means being closed only when both switches are closed, and means dependent upon shifting movement of the shuttle boxes effecting opening of the normally closed switch by a force derived from the lay on shuttle changing operations of the loom.

4. In a shuttle changing loom having a lay provided with shuttle boxes which shift incident to a shuttle changing operation of the loom, a weft detector normally positioned to detect the condition of weft in one of said boxes but receiving a movement by a force derived from the lay in a direction away from the boxes on shuttle changing operations of the loom and tending due to said movement to give a false indication of Weft exhaustion, shuttle changing controlling electric circuit means including a normally open electric switch closed whenever the detector indicates weft exhaustion and including also a normally closed switch, said circuit means being closed only when both switches are closed, and means effecting opening of the normally closed switch by a force derived from the lay on shuttle changing operations of the loom.

5. In a shuttle changing loom having a lay provided with shuttle boxes which shift incident to a shuttle changing operation of the loom, a weft detector normally positioned to detect the condition of weft in one of said boxes, means giving the detector a movement in a direction away from the boxes on shuttle changing operations of the loom, the detector tending due to said movement to give a false indication of weft exhaustion, shuttle changing controlling electric circuit means including a normally open electric switch closed whenever the detector indicates weft exhaustion and including also a normally closed switch, said circuit means being closed only when both switches are closed, and means dependent upon shifting movement of the shuttle boxes and movement of the lay eiTecting opening of the normally closed switch on shuttle changing operations. of the loom 6. In a shuttle changing loom having a lay provided with shuttle boxes which shift incident to a shuttle changing operation and having a weft detector normally positioned to detect the condition of weft in one of said shuttle boxes but having a movement derived from the lay in a direction away from the shuttle boxes during a shuttle changing operation which causes the detector to give a false indication of weft exhaustion, a normally open electric switch closed whenever the detector indicates weft exhaustion, a normally closed electric switch, shuttle changing controlling electric circuit means closed to initiate a shuttle changing operation onl if both switches are closed, and means effecting opening of the normally closed switch during a shuttle changing operation to prevent a false indication by the Weft detector from effecting closure of the electric circuit means.

7. In a shuttle changing loom having a lay provided with shuttle boxes which shift incident to a shuttle changing operation of the loom, a stationary support member, a weft detector supporting member mounted on the stationary member and moved relatively thereto by a force derived from the lay on a shuttle changing operation of the loom, an electric switch mounted on one of said members and normally maintained closed by the other member when said members are in normal position but opened when the detector supporting member is moved by the lay, a weft detector on the detector supporting member tending to give a false indication of weft exhaustion when the supporting member therefor is moved by the lay, a normally open electric switch closed whenever the detector indicates weft exhaustion, and shuttle changing controlling electric circuit means closed only when both of said switches are closed.

HERBERT A. WHITIN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 674,632 Moore et a1. May 21, 1901 1,777,387 Turner Oct. 7, 1930 1,906,957 Gordon May 2, 1933 2,304,181 Kronofl Dec. 8, 1942 

